W. S. Pierce was born in Bourbon County, Kentucky, on January 1, 1821. He volunteered for the war in September 1847, serving in the Independent Company of Kentucky Volunteers under the command of Capt. John S. Williams, which served with the 6th U.S. infantry in Mexico. Arriving after most of the major battles had been fought, he marched with his company from Vera Cruz to Jalapa to Puebla to Mexico City, participating in the occupation of the Mexican capital. He returned home in July 1848 to Owingsville, Kentucky. While in Mexico, he kept a detailed diary of his travels and acquaintances.

According to his newspaper obituary, he brought home from Mexico a remnant of the flag carried by his command. He proceeded to give away small pieces of the flag until only a very small shred of blue remained in the possession of his daughter. He was a Colonel in the Confederacy from 1861-1865. After that war, he was appointed Menefee's County's first county judge, serving one term. Later he served ten years as a circuit court clerk of Menefee and eight years as master commissioner.

W. S. Pierce died at his home in Frenchburg, Kentucky, on September 19, 1893.